* Update index.ts persistentNotifications to include param and conditions for channelType
* Update message for "no recipients mentioned" to not occur for `DM_CHANNEL`.
* Update send message to either start with "Recipients" for DM channel or "@mentioned recipients"
* Include `channelType` in call to `persistentNotificationsConfirmation`
* Fix typo in persisten(t)NotificationsEnabled
* Remove ternary in translatable string
* Add channelType to callback's dependencies
* Make channelType optional